thumb|Swan 65 ketch flying a spinnaker thumb|Fisher30 motorsailer ketch A ketch is a two-masted sailboat whose mainmast is taller than the mizzen mast (or aft-mast), and whose mizzen mast is stepped
1. Compute SHA-256 of OTSCanonicalRecord value → must equal OTSHash 2. Open OTSProofURL → extract Bitcoin block number → must equal OTSBitcoinBlock 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Read CopyrightID inside OTSCanonicalRecord → must equal the CopyrightID above 5. GET OTSVerificationAPI → pre-computed 6-check result from server 6. If all match: this entity was registered on CopyrightChains at OTSTimestamp, independently verifiable on Bitcoin Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x696c1ec475ebe8414152c7bcfdd8124851bd07272698c29d0f0d92d819c33d12. Chain 2 (Bitcoin): anchored in block 953733 (2026-06-15T03:12:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/97b2fbd2-3918-45e7-8f39-bab4807a50cc.json and https://artists.proofprofile.net/proofs/artist/97b2fbd2-3918-45e7-8f39-bab4807a50cc.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).